System of control



-Dec. 27, 1927. 1,654,282

R. E. DE CAMP SYSTEM OF CONTROL Filed Nov. 20, 1912 a /0 l L. I I; r

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. UNITED STATES PATENT OFFICE.

RAY in. DE CAMP, or wILKINsBUnG, rnNN'sYLvANrm ssreNon ro vvnsrmenousn ELECTRIC & MANUFACTURING COMPANY, A conroRArIoN or PENNSYLVANIA.

SYSTEM or CONTROL.

Application filed November 20, 1919. Serial No. 339,511.

My invention relates to control systems and particularly to systems for controlling the sequence of operation of a plurality of electromagnetic switches for controlling the operating circuits of dynamo-electric machines.

The object of my invention is to provide a simplified system of the above-designated character.

Figure 1 of the accompanying drawing is a diagrammatic view of a control system embodying my invention, and Fig. 2 1s a diagrammatic yieW of a portion of a control system illustrating a ditl'erent application The control system illustrated in Fig. 1 embodies a motor 1; a starting resistor 2 for controlling the value of current traversing the circuit of the motor 1; a circuitv 1, 5, 6 and 7 when the coils are energizedto a predetermined degree. The contactors 5 and 6 are provided With interlocks 141 and which respectively establish circuits for coils 10 and 11.

The relays 12 and 13 are actuated to their open positions by a current of predetermined value traversing the correspomhng actuating coils 16 and 17 that are in series circuit. The relays 12 and 13 are respectively adapted to shunt re stors 18 and 19. The resistor 18 is in series-circuit relation to coil 8 and interlock 14, and the resistor coil 9 and interlock 15.v The resistors 18 and 19 are of such value that the energy supplied to the several c0ntactor-actuating coils 8,, 9', 10 and 11 through the corresponding resistor, is not suflicient to actuate the contactors to their closed positions but is sufiicient to maintain them in these positions after they have been closed by a current of larger magnitudei ot' the principles embodied in my invention. 7

with different portion of the main motor 19 is connected in series-circuit relation to In order to operate the system illustrated in Fig. 1,.the circuit breaker 3 is closed to energize the system. The initial rush of current through armature 1 and resistor .2 actuates relay 12 to an open position and inserts resistor 18 in series relation With the coil 8 01' the contactor 4L. 1 The insertion of the resistor 18 in the circuit of the coil 8 insures a degree of energization of the coil that is not suilicient to actuate the contactor 1 to itsclosed position and the same is, therefore, maintained in its open position until the current traversing motor armature 1 decreases to a predetermined value that is sutficiently small to permit relay 12 to close. The resistor 18 is thereby shunted from the coil circuit, and the total voltage across the motor armature and resistor 2 is applied to the actuating coil 8. The contactor i: then closes to complete a shunt circuit for a portion of the resistor 2.

. It Will be noticed that, at this step in the sequence of operation of the control system, the main motor current is diverted from the actuating coil 16 of the relay 12 and traverses the actuating coil 17 of the relay 13. Relay 12 is, therefore, maintained in} its closed position during this period of transition, and relay 13 is actuated to its open position by the rush ofcurrent caused by the closing of contactor 1. The opening of the relay inserts the resistor 19 in the circuit of the actuating coil 9. The relay 13 is maintained in its open position until the current traversing its actuating coil dce creases to a predetermined value that is sufiiciently low to permit its closing. As soon relay 13 shimts the resistor 19 by dropping to its closed position, .contactor 5 is closed, and an additional portion ofthe resistor 2 is excluded from the circuit: ot the main motor 1. This another step in. the motor 1.

WVhen the contactor 5 is closed, the currenttraversing the main motor circuit is again diverted and traverses the portion of the circuit embodying the coil 16 of the relay 12. i The heavy armature current actuates the relay 12 to its open position and the resistor 18 is reinserted in the circuit of coil 8. The-resistor 18 is of such value that the current traversingthecoil 8 of contactor 4, when the resistor'18 is reinserted in the control circuit, is of suiiicient value to maintain contactor 4 in its closed position.

operation completes This current is not, however, of suiiicient value to actuate the contac'tor from its open position to its closed position.

(lontactor 5 is provided with the interlock let which completes a circuit for the actuating coil when switch 5 is closed. This controls the sequence of operation ot the various switches. Since the main n'mtor current traverses the actuating coil of relay 12 during this period in the operation oi? the system, the relay 12 is actuated to its open position and the resistor in is inserted in series with the actuating coil. 10 of contactor- 6.

hen the current tiaveruiirethe main motor circuit decreases to a prcdeterniincd minimum value, the rela 12 again closes to shunt the resistor 18 and thereby etlect the closing oi? contactor (3. This estahlii-ihcs a circuit in shunt relation to an additional portion of the resistor 2.

The main motor current is again (lVGI't d to the port-ion or the circuit containing the actuating coil 17 of relay l3. A circuit for the actuating coil ill of the contactor 7 is completed by interlock it) that is closed when contactor (i closed. As soon as relay 13 drops to its closed position, the coil 11. is energized to such degree as to close the contactor 7 which completes a sln'int circuit for the entire resistor 2.

Fig. 2 shows a portion oi a control system embodying a modification of the principles involved in the system illustrated in Fig. l. The control circuit shmvn in Fig. 2 coinprises a relay that is controlled by the current traversing a main circuit 21 which may be connected to an electric apparatus. A resistor 22, which is similar to resistors 18 and 19 of Fig. 1, is shunted by the relay 20. When the relay 20 is actuated to an open position by a current of predetermined value traversing circuit 21, the resistor 22 is inserted in the control circuit of a plurality oi electromagnet coils 23 and 24-. for lltt.llill1lll) contactors 25 and 26. Connections in the main circuits 27 and 28 are controlled by contactors 25 and 2c.

The contactor 25 is provided with a in terlockingz' device 29 that controls the sequence of operation of the two contaclors 25 and The method of operation of the portion of the control circuit illustrated in l 2 is sul'istantially the same as that just described in connection with Fig. 1. The interlocking system is, however, slightly different in that, instead of en'iploying interlocks associated with contactors controlled by one relay to establish a sequence of operation for contactors controlled by a second relay, as in Fig. 1., the circuits shown in Fig. 2 illustrate a method of controlling the sequence of operation of a plurality of contactors controlled by a single relay.

The resistor 22, shown in 2, is of such value that contactors 25 and 26 are maintained in their closed positions otter they have been actuated thereto, but the value of the resistance is sullicienliy high to prevent the initi ll operation oi? the contactors. Ass-aniline that a current oi? suiiicient (J value to actuate clay 20 traverses the circuit. 2l, contactors 25 and 2'6 are maintained in their open positions un'il this current lecreases to a value sullicicntly sn'iall to permit the relay to close. Coil 25% then receives tull voltage, since the intervening resistor is shunted by relay 20, and c nitactor is actuated to its closed. p .:silion to estahl 'n certain circuit ltilliTlUlll-i tor the main circuit The interlock 2%) completes the circuit tor the coil 2t when contactor 25 is closed. it is assumed that another temporar rush oit current traver: w circuit 2 by r on of the closure of ct tactor 2: 3, the coniactor 28 is maintained in as open position until the current tra ersing circuit 2i decreases to a mine permitting; the rela to close. When the relay 2t) closes, eontactor 26 establishes certain circuit relations tor the main circuit From the above discussion, it will be run derstood that the function ot the relays is to maintain the succeeding contra-tor to be acl uated in its open pox tion until the current traversingthav portion oi the motor circuit, which includes the actuating coil for the relay, decreases to a predeteriuined ralue and permits the relay to shunt the resistor. After he craitactor is closed, the reinsertiou oi the resistor in the circuit the actuating; coil will. not (.lllltll. the contactor to open because the current traversi. ,5 l Hstor is suiiicient to maintain the contactor in its closed position.

The portion o't the control circuit illustrated, in Fi 2 illustrates this same ,e en ral if 1 l.

n'iaiciple as applied to cont; circuits cur-- iodyinc any desired number o't conliuaors :mtuated by a single relay.

lilithcr ol these rvsleins ol' control lll2'.\' be employed tor operating any electrical apparatus ri-uiuirinp; a. pin alily ot coulaclors operated in accordan e with certain electrical coiulilions and in a given sequence. The order in which the contzu-tors close is controlled. by arranging interlocks on the respective contactors or between. contzwtors controlled by dill'erent relays. .ln this manner. any desired sequence of operation of the series of contactors can be established.

Although I have described a simple and preferred term of my invention with a single modification, it will he ni'iderstood that other applications are possible, and I desire, therefore, that only such limitations shall be "nnposed as are indicated in the appended claims.

till

I claim as my invention:

1. A control circuit comprising a group of electromagnetically-controlled switches, resistor in the control circuit of said switches to prevent the actuation of said switches, a relay adapted to effect the actuation of said switches by temporarily rendering said resistor ineffective, a second group of switches, a second relay for effecting the actuation of said second group of switches, operating coils for said relays, and interlocking means for subjecting said coils alternately to the motor current.

2. A system of control comprising a main circuit, a relay actuated by a predetermined value of current traversing a portion of said main circuit, means for diverting current from said portion of said main circuit, means for reestablishing a main flow of current through said portion of said main circuit, a plurality of switches for controlling said main circuit, electromagnetic coils for controlling the operation of said switches, a resistor in circuit with said coils for preventing the operation of said switches but permitting said switches to be maintained ill the respective positions to which they have been actuated, said relay being adapted to efiect the actuation of said switches by temporarily rendering said resistor ineffective. 1

3. A system of control comprising a main circuit, a relay actuated by a predetermined value of current traversing a portion of said circuit, a second relay actuated by a predetermined value of current traversing a second portion of said circuit, means for diverting current from one portion of said circuit to the other portion of said circuit, a group of switches controlled by said first relay for controlling said main circuit, coils for controlling the operation of said switches, a resistor in circuit with said coils and, adapted to prevent the operation of said switches but permitting said switches to be maintained in the position to which they have been actuated, a second group of switches controlled by said second relay,

and interlocking means controlled by said second group of switches for controlling the 1 sequence of operation of said first group of switches.

4. A system of control comprising a main circuit, a relay actuated by current of a predetermined val'ue traversing a portion of said circuit, a second relay actuated by current of a predetermined value traversing a second portion of said circuit, a plurality of switches controlled by said relays for controlling said main circuit adapted to successively divert current from one portion of said circuit to said second portion of said ed to effect the actuation of said switches by rendering said resistors temporarily ineffective, and interlocking means for effecting the actuation of switches controlled by said coils alternately from said groups in accordance with a given sequence.

5. The combination with a motor having an armature and an accelerating resistor therefor, of an accelerating coil in series relation with said resistor, a second accelerating coil for connection in shunt relation to the first named accelerating coil and means for alternately diverting current from sald coils.

6. The combination with a motor having an armature and an accelerating resistor therefor, of an accelerating coil in series relation with said resistor, a second accelerating coil, and means for diverting the motor current through said coils alternately and through different portions of said resister.

In testimony whereof, I have hereunto subscribed my name this 24th day of Oct. 1919.

RAY E. DE CAMP. 

